Sand mixer for sand blast machines



Aug. 22, 1933. R RUEMELlN 1,923,329

SAND MIXER FOR SAND BLAST MACHINES Filed June 24, 1929 me/wko@ [Bicho/rd lzwmelw Patented Aug. 22, 1933 @NEED STATES r oFFcE 4 Claims.

My invention relates to a sand mixer box for sand blast machines for regulating the flow of sand from the supply tank to the mixer chamber. A primary feature resides in providing means for regulating the flow of sand by a flexible member which depends virtually straight from the sand tant: and wherein means operate on the flexible tubular member to ilatten the same to decrease to the point of cutting off the flow of sand and to regulate the flow by the degree of flattening of the flexible member.

A feature of my sand mixer resides in a mixing box having a casing with a cover member which may be readily removed without disturbing the inner parts or for replacement of the same and to expose the parts within the mixing box when the cover is removed.

It is also a feature of my sand mixer box to provide lever operating means which are adapted to operate the vise-like pinching members for flattening the tubular flexible member and in means for holding the lever in a set position so that the flow of the sand may be regulated and maintained at a set pre-determined flow into the mixing box.

In this mixer box I provide means of causing the sand to flow from the supply tank into the mixer box in a conical or pyramidal formation ol' the sand which is directly in the path of the compressed air passing to the sand blasting nozzle. The structure of my sand mixer box is such that compressed air also flow to the blasting nozzle by passing around the sand cone, which condition is particularly prevalent at the time when 'D5 a sand cone is formed in the bixer box, such as would take place when the compressed air is shut on? for a time through the mixer box.

This permits the mixer to pick up the sand and 4 carry it off around the cone and eventually directly through the cone at the start of the ow of air through the mixer after it has been shut olf and the sand ilow permit it to remain at a set flow.

'Ihese features together with other details and objects of the invention will be more fully and clearly set forth in the specication and claims.

In the drawing forming part of this specification:

Figure 1 illustrates a detail of my mixer box for sand blast machines, showing the cover of the same removed, illustrating in section a portion of the supply tank and also the operating lever.

Figure 2 is a section on the line 2-2 of Figure 1, showing the iiexible sand feeder in the mixing box closed.

Figure 3 is a similar section to Figurer 2, showing the ilexible sand feeder open.

I have illustrated in the drawing my sand mixer box A which is attached by the pipe 10 to the sand tank B.

The sand mixerv box A is formed with a casing portion 11 having a flange 12 to which the cover 13 is secured by suitable bolts extending through the openings 14 in the cover and flange 12.

The sand mixer box A is supported by the pipe l() directly below the sand supply tank B and in a manner so that the sand can flow from the tank B into the mixing chamber 15 of the v'ZO sand mixer box A. Extending from the pipe l0 I provide a nipple 16 within the mixer A which is adapted to support the iiexible sand feeder or hose 17 with the free end 18 of the sand feeder depending into the chamber l5 in the lower portion of the mixer box A.

The casing ll of my sand mixer box A is formed with an inwardly projecting shoulder portion 19 on one side which extends closely adjacent the` side of and near the free end 18 of the flexible sand feeder 17. On the opposite side to the shoulder 19 I provide a lever 20 formed with an engaging lug 21 which is adapted to be positioned as illustrated in Figure 3, in a manner so that when the lever 2U is operated the lug 2l will pinch the free end 18 of the llexible sand feeder 17 against the inwardly projecting lug 19 and tend to close the flexible sand feeder 17, as illu.- trated in Figure 2. The operation of the lever will partially close or completely close olf the flexible sand feeder 17 and stop the flow of sand into the mixer A.

The lever 20 is adapted to be operated by the shaft 22 which is rotated by the lever 23 secured to the outer end of the same and by means of the 95 friction knob 24 which is threaded in the upper end 25 of the lever 23 a frictional Contact can be made at 26 with the quadrant member 27 which is fixedly secured in a manner so that the lever 23 can be set to position the lever 20 in the ,100 sand mixer A in the desired position, either to4 shut olf the sand flowing from the supply tank B into the mixer A, or to partially close the sand `feeder 17 or to open it wide and permit the sand to iiow freely into the mixing chamber 15 of;l the mixer A.

The compressed air is passed through the mixing chamber 15 by the inlet 28 and the outlet 29. The outlet 29 leads through the hose 30 to the blasting nozzle 31. S

In the use of my sand mixer A compressed air is passed through the mixing chamber 15 and the flexible sand feeder is set by the pinching means to cause the correct amount of sand to flow into the mixing chamber 15. It is apparent that the flow of sand can be very easily regulated by properly setting the operating lever 23 which regulates the lever 20 and causes the lug 21 to pinch the flexible sand feeder 17 more or less as may be desired. It sometimes becomes necessary to shut off the sand blast and this is usually done by shutting 01T the compressed air, leaving the flow of sand set to flow into the mixing chamber 15. This permits the shutting on of the sand blast Without changing the iiowof the mixture of the sand and thus keeps the mixture of sand and air the same throughout the entire work of sand blasting in a particular operation. This is Very important because after the sand has been lset to flow in the operation of a particular piece of sand blasting work it is essential that the mixvture be not changed until the work is completed.

I am able to accomplish these results very readily :with my sand mixer A.

lAnother feature of the invention which is important resides in the simplicity of structure. The feedermay be pinched readily to any degree and.V to close off thesame anda very strong .and

substantial hose or fiexible sand feeder member 17 maybe provided having long wearing qualities and being highly resistant to the action of the air and sand past the same which is very important.

.will pass over and around the cone of sand, such as C, until the sand cone isdiminished to a certain. extent and then the air blast will pass directly through the passageway l5 carrying the iiow of sand from the feeder 17 through to the .nozzleBL It is readily apparent that the removal of the .cover 13 may be easily Vaccomplished and the inner parts adjusted or changed in the sand mixer A. The advantages of my mixer are quite apparent andI have found the same to bev very desirable in use in the mixing of sand blasting.

Inaccordance with the patent statutes I have describedthe principles of my sand mixer for vsandblast generators and while I have illustrated and described a particular formation and operation of the parts, I desire to have it understood that the same is only suggestive of a means of. carrying out the principles of my invention and .that obvious changes may be made Within the .scopeof the following claims without departing from the purpose and intent thereof.

I claim:

1. A sand mixer for sand blast machines including, a casing, a removable cover extending across one side of said casing, a nipple projecting into said casing, a iiexible tubular member secured to said nipple and having a free open end extending therefrom, lever means and shoulder means for pinching the free end of said flexible member closed, said nipple and flexible member being connected with a source of supply of blasting sand, and an air chamber into which the free end of said fiexible member depends adapted to be connected with a source of compressed air and having an outlet therefrom.

2. A.. sand mixer for sand blast machines including, a casing, a chamber formed in said casing, a iiexible tube extending in said chamber connected on one end with said casing and to a source of supply of blasting sand, the other end of said flexible member being freely disposed and depending through said chamber, an air chamber formed below said first chamber having a horizontal inlet and outlet passageway to permit air to. be passed under pressure therethrough, and means for pinching the free end of said exible member closed to shut off the source of supply of blasting sand to said air chamber in a manner to form a cene-shaped piie of blasting sand in said air chamber extending with its apex from the free end of said iiexible member.

. 3. A sand and air mixer for sand blasting equipment including, a casing, means for connecting said casing with a source of supply of blasting sand, a chamber formed in said casing, a exible tube depending from the top of said chamber with one end secured in a manner to connect with the source of supply of sand and the other end freely disposed in said chamber, means for pinching the free end of said iiexible member closed toshut the same, and an air chamber 'formed below said fiexible member and into which it is adapted to project, said air chamber having a connection with a virtually horizontally extending source of compressed air and an outlet to a sand blasting nozzle and providing a chamber wherein a conical-like pile of sand is formed with a free passage of air around the sand when the free end of `said vflexible member is partially and entirely closed.

4A sand and air mixer including, a casing, an upper chamber formed in said casing, a lower chamber formed below said upper chamber, a iiexible sand shut-off extending through said upper chamber from a source of supply of sand and having its free end depending into said lower chamber, said lower chamber providing an .fir inlet and outlet means extending angularly in relation to said flexible member, and means for pinching the free end of said flexible member Ato open and close the same.

RICHARD RUEMELIN. 

